新型缺陷接地结构带通滤波器研究

Novel Defected Ground Structure Bandpass Filter

在传统缺陷接地结构(DGS)哑铃型微带线的基础上,提出了一种新型DGS,即将哑铃型DGS中的长方形缝隙变为蛇形缝隙。借助于Designer软件,得到哑铃型DGS与新型DGS的仿真结果。在相同缺陷面积条件下,新型结构可获得更低的衰减频率,而在衰减频率相同时,所占用缺陷面积也更少,衰减频率降低约3 GHz,缺陷面积减少为原来的30%左右,减小了对级联电路的辐射影响,提高了系统的电磁兼容性。分析了结构参数变化对阻带特性的影响,并将新型DGS应用于紧凑结构带通滤波器(BPF)的设计。仿真结果验证了新型DGS带通滤波器的有效性和可行性。

Based on the traditional dumbbell defected ground structure （DGS） for microstrip line, a novel DGS is proposed, that is, changing the rectangle gap of the dumbbell DGS into snake-like gap. With the Designer software, the simulation results of the dumbbell and the new DGS demonstrate that the latter can obtain lower attenuation frequency in the same defected area and can take up less defected areas at the same attenuation frequency. The attenuation frequency decreases about 3GHz in the same defected area, and the defected area lessens to the original 30% at the same attenuation frequency. The radiation reflection to cascaded circuits is reduced and the electromagnetic compatibility for the system is increased. The influences of the new DGS dimensions on stop-band characteristics are discussed, and the proposed DGS is applied to the design of a compact band-pass filter. The validity and feasibility of the new DGS bandpass filter are verified by simulated results.